Search engine optimization is a familiar concept for most online businesses. But Amazon SEO operates under entirely different rules than Google SEO, and confusing the two is one of the most common mistakes sellers make. Amazon’s search algorithm does not care about backlinks, domain authority, or content depth. It cares about one thing: which product is most likely to generate a sale for the customer entering a search query.
Understanding how this algorithm works is not optional for sellers who want organic visibility on the marketplace. Paid advertising can drive traffic, but organic rankings determine long-term profitability. Every sale that comes through organic placement is a sale without advertising cost. For sellers managing large catalogs, the compound effect is massive, which is why listing optimization has become the core service of every serious Amazon SEO agency and the first lever experienced sellers pull before increasing ad spend.
So how does Amazon’s search algorithm actually decide what to show?
The Algorithm’s Core Logic: Relevance Meets Performance
Amazon’s search algorithm, historically known as A9 and now widely believed to have evolved into what some refer to as A10 or COSMO, follows a two-stage logic. First, it determines whether a product is relevant to the search query. Then, it ranks relevant products based on performance signals.
Relevance is binary at the most basic level. If a customer searches for “stainless steel water bottle 1 liter” and those terms do not appear in the product’s indexed fields, the listing will not show up. It does not matter how many sales the product has or how strong its reviews are. Without keyword relevance, the product is invisible for that query.
Performance ranking is where it gets competitive. Among all relevant products, Amazon ranks them based on signals that indicate purchase likelihood. The strongest signals are click-through rate from search results, conversion rate on the product page, and total sales velocity. Products that get clicked and purchased consistently rise in rankings. Products that get impressions but few clicks, or clicks but few purchases, fall.
This dual logic means that Amazon SEO requires work on two fronts simultaneously: ensuring the listing contains the right keywords, and ensuring the listing converts visitors into buyers.
Keyword Placement: Where and How It Matters
Amazon indexes keywords from specific fields in the product listing. Not all fields carry equal weight, and understanding the hierarchy is essential for effective optimization.
The product title carries the most weight. Keywords placed in the title have the strongest influence on which search queries trigger the listing. Amazon allows up to 200 bytes for titles in most categories, and every word should be intentional. The best-performing titles follow a structure that places the most important keyword first, followed by key attributes like size, material, quantity, and use case.
Bullet points are the second most important indexed field. They serve a dual purpose: keyword coverage and conversion. Each bullet point should address a specific customer concern or product feature while naturally incorporating relevant search terms. Keyword stuffing, cramming terms without context, is counterproductive. Amazon’s algorithm increasingly evaluates semantic relevance, and customers who encounter unreadable bullet points are less likely to purchase.
Backend search terms are a hidden field not visible to customers but fully indexed by Amazon. This is where sellers should place keywords that do not fit naturally into the title or bullet points: synonyms, alternate spellings, related terms, and long-tail variations. The field has a 249-byte limit, and every byte counts. Common mistakes include repeating keywords already in the title, using commas or punctuation that waste space, and including brand names that Amazon already indexes separately.
The product description and A+ Content were historically not indexed, but Amazon has changed this. A+ Content text is now searchable, which means it serves both a conversion and an SEO function. Sellers who treat A+ Content as purely visual are missing an opportunity to capture additional keyword coverage.
Conversion Rate: The Ranking Factor Sellers Underestimate
Many sellers focus exclusively on keywords and neglect the other half of the equation: conversion rate. Amazon’s algorithm heavily rewards listings that convert well because a high conversion rate directly aligns with Amazon’s business model. Amazon makes money when products sell. Listings that turn browsers into buyers get pushed higher.
Conversion rate is influenced by several factors beyond keywords. Product images are the most impactful. The main image determines click-through rate from search results, while gallery images and A+ Content influence on-page conversion. Price and perceived value play a critical role, particularly in categories where multiple similar products compete for the same keywords. Reviews and ratings provide social proof. A product with 4.5 stars and 500 reviews will outconvert an identical product with 3.8 stars and 40 reviews, regardless of how well the listing is optimized for keywords.
This is why Amazon SEO cannot be treated as a purely technical exercise. It requires an integrated approach that combines keyword optimization with listing quality, competitive pricing, and review management.
Sales Velocity and the Flywheel Effect
Amazon’s algorithm is self-reinforcing. Products that sell well rank higher. Higher rankings lead to more visibility. More visibility leads to more sales. This is Amazon’s flywheel, and it is the reason why early momentum matters so much for new products.
For established products, the flywheel works in their favor. Strong sales history provides a ranking buffer that makes it difficult for new competitors to displace them. For new products, breaking into established rankings requires an initial push, typically through advertising, promotions, or external traffic, to generate the sales velocity needed to trigger the flywheel.
This is also where PPC and SEO intersect on Amazon. Advertising drives sales that improve organic rankings. Improved organic rankings generate sales without ad spend, which lowers the overall cost of customer acquisition. Sellers who treat PPC and SEO as separate disciplines miss this connection and typically overspend on advertising in the long run.
Conclusion
Amazon’s search algorithm in 2026 is more sophisticated than ever, but its core logic remains unchanged: show customers the products they are most likely to buy. Sellers who understand this logic and optimize for both keyword relevance and conversion performance will build organic visibility that compounds over time. Those who guess at keywords, neglect listing quality, or treat SEO as a one-time task will continue paying for every sale through advertising, a model that becomes increasingly unsustainable as competition grows.
Peyman Khosravani is a seasoned expert in blockchain, digital transformation, and emerging technologies, with a strong focus on innovation in finance, business, and marketing. With a robust background in blockchain and decentralized finance (DeFi), Peyman has successfully guided global organizations in refining digital strategies and optimizing data-driven decision-making. His work emphasizes leveraging technology for societal impact, focusing on fairness, justice, and transparency. A passionate advocate for the transformative power of digital tools, Peyman’s expertise spans across helping startups and established businesses navigate digital landscapes, drive growth, and stay ahead of industry trends. His insights into analytics and communication empower companies to effectively connect with customers and harness data to fuel their success in an ever-evolving digital world.
